The invention pertains to liquid dispensing nozzles of the type used on gasoline pumps. A gasoline station often has two islands and each island will have from three to six gasoline pumps. These pumps consist of a fluid pump, fluid meter, hose and nozzle. The nozzle commonly includes a flow control valve and an automatic shut-off unit. The automatic shut-off unit senses when a tank that is receiving fuel is full and stops the fuel flow accordingly.
Service stations can be of the full serve type where an attendant operates the pump or of the self-serve type where the driver operates the pump to dispense fuel into his or her own vehicle. Most times, the fuel delivery system works flawlessly and the fuel transfer is made without spillage. However, there are rare instances when a significant fuel spillage can occur.
The most common cause of these incidents is the motor vehicle operator driving the vehicle away from the pump before the pump has been shut-off. This can be due to inattention on the driver's part, or the attendant being rushed and forgetting to remove the nozzle. Whatever the cause, the scenario involves the nozzle tip remaining in the car's fuel inlet as the vehicle drives off. As the fuel hose reaches its maximum extension, any of the following can occur: the pump can be pulled over, the hose can break or the nozzle tip can break off from the nozzle. Usually, the nozzle tip includes a weakened wall section so that the latter event is favored. This saves the majority of the pump equipment from being damaged, but a major spillage of gasoline can still result.
When the nozzle tip is separated from the nozzle body, the automatic shut-off is either disabled or not in an actuable orientation. Therefore, if the pump is on, gasoline will continue to flow from the nozzle and spill onto the ground. Liquid will not stop flowing until the attendant manually operates the shut-off valve. In some cases, a short but significant amount of time may pass before the attendant becomes aware of the situation. Even in a short period of time, in excess of a hundred gallons of fuel may discharge from the nozzle. Spilled gasoline in any amount can be an extreme fire hazard, and at a service station, a gasoline fire can be catastrophic.
Therefore, it is the objective of the invention to provide a mechanism which is low in cost and which will automatically stop the flow of fuel in the event that the nozzle tip is separated from the nozzle.